Advertisement

Advertisement

Mothers hold key to studying child development

By PHYLLIDA BROWN

A MAJOR study of child development begins in Britain this week – not
with newborn infants but with their expectant mothers. The study, entitled
Children of the Nineties, will study 11 000 infants to be born next year
and in subsequent years until at least 1998. It is the first long-term project
to take pregnancy into account in the health of the child.

The study aims to measure the relative importance of a wide range of
genetic and environmental factors on child health and behaviour. The organisers
of the study say that teams in six other countries – Belgium, Sweden, the
Soviet Union, Czechoslovakia, Greece and Spain – are planning to collaborate.
Money for the British project is coming partly from the government and partly
from charities, including the Wellcome Trust and the Asthma Research Council.

It is not the purpose of the study to screen individuals for genetic
diseases, says Jean Golding, one of the organisers at the Institute of Child
Health at the University of Bristol.

Nor are the researchers trying to identify new genes. They are trying
to measure the interplay of environment and heredity in specific conditions,
such as allergies and asthma, where both factors may be involved. The aim
is to discover whether environmental factors – such as diet – affect the
health of the individual.

Advertisement

Much of the study will concentrate on specific genes that have already
been characterised – for example, a family of genes called the cytochrome
p450 genes, whose products are involved in detoxifying the body of foreign
chemicals and substances from the diet, such as fatty acids.

One gene in this family, called cyp-2-D6, is mutated in about 10 per
cent of the population. Individuals with the mutation are unable to manufacture
the gene product, cytochrome p450, which detoxifies certain basic compounds
and the class of heart drugs known as beta-blockers. As a result, they cannot
tolerate the compounds. Jeff Idle, a geneticist at the University of Newcastle
upon Tyne, will be analysing DNA from all 11 000 babies for this particular
mutation at a cost of Pounds sterling 55 000.

The researchers will collect routine samples of blood, urine and placental
tissue from the mothers and blood samples from the babies at birth. A laboratory
will culture a line of lymphocyte cells from each baby for a permanent source
of DNA. In addition, both parents will complete detailed questionnaires
about their diet, lifestyle and family history. In 1998, the children will
undergo standard psychological and intelligence tests.

The confidentiality of the data is crucial. All the information will
be coded in such a way that not even the organisers will be able to trace
any findings back to individuals who participate in the study.

One woman who has participated in the pilot studies and who will also
take part in the main project, is prepared to be identified. Catherine Gratze
commented: ‘There are a lot of things that could affect you and your baby
that you can perhaps change. I hope that such a large study can prove at
least whether something is or isn’t a problem.’

Participation in the study is voluntary but more than two years of pilot
studies suggest that more than 90 per cent of people asked are willing to
do so, says Golding.